Update babylon.camera.ts
Update babylon.camera.ts

Fixing TypeScript error
The function is taken from the WebVR camera, but TypeScript takes "this" as the camera class.
Temechon/Babylon.js,jbousquie/Babylon.js,RaananW/Babylon.js,Temechon/Babylon.js,NicolasBuecher/Babylon.js,jbousquie/Babylon.js,Kesshi/Babylon.js,BabylonJS/Babylon.js,sebavan/Babylon.js,abow/Babylon.js,abow/Babylon.js,Kesshi/Babylon.js,Kesshi/Babylon.js,BabylonJS/Babylon.js,Hersir88/Babylon.js,Temechon/Babylon.js,NicolasBuecher/Babylon.js,RaananW/Babylon.js,NicolasBuecher/Babylon.js,Hersir88/Babylon.js,jbousquie/Babylon.js,BabylonJS/Babylon.js,Hersir88/Babylon.js,RaananW/Babylon.js,sebavan/Babylon.js,sebavan/Babylon.js,abow/Babylon.js